1. Field of the Invention
This invention relates to a knitting machine, particularly a straight knitter, and to a stopping mechanism which may be triggered to stop the machine in the event of danger to the machine operator.
2. Description of the Prior Art
Knitting machines of this type are disclosed, for example, in "Strickerei-und Wirkerei-Technik" volume of Apr. 1963 No. 4. In such knitting machines, a machine stopping mechanism is triggered to turn the machine off to provide protection against possible pinching of the operator's hand between any one of several movable parts of the machine and a fixed part of the machine during manipulation while knitting is being carried out.
Knitting machines generally have very many movements of individual units of the machine which take place during machine operation. Some of these units involve in turn many movements, such as, for example, a gear unit may be arranged and fitted in such a way that such units are not a source of possible injury to the operator of the machine. However, other units cannot be covered or shielded from the operator, or if shielded, are not sufficiently shielded since their mode of operation makes such shielding impossible.
For example, it is necessary for the slide of the knitting machine to move into the area of one or more stops which are stationarily mounted on the machine frame so as to enable the stops to actuate the slide and cam bolts. Although it is possible to cover the area in which the stops are located in such a way that the operator can not reach his hand into this area, an area of danger still exists at the place where the cover or shield exists, particularly the sides of the cover, thus the cover itself creates an area between the cover and the slot where pinching of the operator's hand may occur. Practical safety devices for such areas of danger have not hitherto been satisfactorily effected.
Therefore, it is an object of the present invention to provide a safety device for a knitting machine which provides sufficient protection against injuries and particularly against injuries at places where pinching of the operator's hand may occur between stationary parts of the machine and its movable parts.
According to the present invention, this object is achieved in that in the area of each of the parts which are stationarily mounted on the knitting machine in the vicinity with a movable part that could cause pinching of the hand therebetween, a hood is provided which is mounted for movement in a direction in which pinching could occur which extends across stationary part and between that stationary part and the movable part and by the provision of a stopping mechanism for stopping the operation of the knitting machine which is triggered by movement of the hood by contact of the operator's hand. The safety device of the present invention insures, therefore, that after the hood covers the area where pinching could occur, pinching is in no way possible despite further travel of the movable part over a necessarily occuring braking distance after the knitting machine has been switched off by the stopping mechanism since the hood, being movable, deflects over the braking distance of the movable part without uncovering the stationary part. Preferably, the hood is swivelable and may be mounted by way of a parallelogram guide system. However, in the alternative, the hood may be mounted for translatory displacement, particularly in guide tracks.
The stopping mechanism may comprise a microswitch which is opened and closed upon movement of the hood and which is employed for triggering the termination of knitting machine operation by opening a circuit to the microswitch.
The hood is preferably movable to a distance equal to the greatest braking distance of the movable part of the knitting machine after triggering of the brake or stopping mechanism plus a reserve distance. This insures that even in the case of differing speeds and resultant differing braking distances of the movable part that may cause pinching of the operator's hand, the distance through which the hood swings or is linearly displaced is sufficient to insure with certainty that pinching is avoided.
The safety device in accordance with the present invention may be used at various locations on the knitting machine, for example in the area of stops, of the drive mechanism, and of an automatic starting comb.
An embodiment of the invention for use in a particular case is illustrated in the drawing and will now be described in greater detail.